[TYPO3-dev] Testing TYPO3 caching vs. [FE][pageCacheToExternalFiles]

["Marc Wo"hlken [quadracom]"]

Hi!
Martin Kutschker schrieb:
>>> Fine should we remove the "Using MySQl indexes effectively" section
>>> then? Because the information is wrong. Randomly adding indices on
>>> single fields improves nothing.

I suppose no one is trying to add indexes randomly. The suggested
columns "hidden", "deleted" and "sorting" are well chosen.

> I see really no point in those indices as it will probably never be used
> by TYPO3. Perhaps an index on (sorting,deleted,hidden) will make sense,
> but two indices on (deleted) and (hidden) are IMHO a wrong use of indices.

A compund index does only make sense if the included columns are really
used together. This SHOULD be the case with "hidden" and "deleted" as
these are some of the crucial columns for enableFields().

If someone uses a compund index (hidden, deleted) that would only
increase db performance when a sql query contains
1) hidden and deleted
2) only hidden

In case of queries containing deleted only there would be no positive
effect.

Keeping this in mind it is a good starting point to use 2 indexes. If we
can verify both columns are (nearly) always used together a compund
index would make more sense.

BTW: Does anyone know how to build indexes for starttime and endtime
columns? Probably a simple 4 Byte index is not optimal as it does not
provide any grouping of values.

-- 
...........................................................
Marc Wo"hlken

Quadracom - Gottschall, Proffe & Wo"hlken

Fedelho"ren 45a                 WWW: http://www.quadracom.de
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